Mattress foam comes in multiple different types: memory foam, polyurethane, and latex. Memory foam is a type of polyurethane foam that has lower resistance so it reacts and slowly reforms when pressure is released. It generally makes up the surface layers of a mattress.
Polyurethane comes in multiple different forms - making it useful in the middle and base layers of many foam and memory foam mattresses.
Latex is the natural alternative to memory foam and polyurethane foams. It is created from sap from a rubber tree and is treated to create different densities to cover both soft and firm requirements. Like rubber, it is highly responsive and has a bounce that some sleepers love and some others hate.
Pros: Depending on the foam type, it can be quite comfortable, safe, and responsive.
Cons: Lower quality foams can break down quickly, causing sagging issues within only a few months or years.
Innerspring systems describe mattresses made with coil systems. Traditional innerspring mattresses were made with interconnected coils, providing structure to the bed. In recent years, some have used 'innerspring' to describe newer pocket spring systems that are independent and offer greater comfort.
In general, most use 'innerspring' to describe the traditional mattress styles and those that purchased a mattress in the 20th century are very used to these types of beds.
The interconnected spring systems offer a high amount of durability and support, but there are complaints of aggravated pressure points and discomfort despite comfort layers of foams on the surface.
Pros: Durable materials and traditional even feel.
Cons: Pressure point discomfort and motion transfer issues.